FIELD OF THE INVENTION
The production of a synthesis gas in a conventional gasifier usually embodies the partial oxidation of a fuel mixture at a relatively high temperature. The resulting products of combustion include the desired synthesis gas, together with an amount of uncombusted effluent.
When the fuel mixture is comprised of a solid material such as coke or coal grounds, the composition of the coke or coal can be such that varying amounts will not be combusted and will be passed through the gasifier and remain as a solid. While a considerable amount of the solid effluent components will be carried into the gasifier quench chamber, at least a part of said solid effluent will be retained on the gasifier walls and form a slag. When in a hot plastic state, the slag will gradually flow down to the gasifier quenching bath, or eventually solidify when the gasifier is closed down and the temperature is reduced.
At some point in the synthetic gas production process, it will be apparent that the presence of an excessive amount of slag within the gasifier is impeding the gasification process. At such time, the gasifier is manually shut down for the specific purpose of melting the slag or of effectuating a deslagging operation.
Such an operation is comprised basically of introducing a combustible mixture to the gasifier's combustion chamber such that when a sufficient elevated temperature is reached, the slag will melt and by gravity flow pass into a quench bath.
One detriment to this procedure becomes apparent, particularly when the partially combusted mixture includes an amount of vanadium in its composition. The subsequent deslagging operation will be impaired by this element's presence most often resulting in damage to the gasifier constricted throat at a greater rate than the rest of the gasifier refractory. The latter will tend to be physically eroded or corroded away by the accumulation of slag about this narrowed portion of the effluent flow path and the thermal shock to which it is often subjected.
Stated briefly, it is therefore, an object of the invention to provide a novel gasifier throat structure which includes a cooling system embodying a circulating medium.